text: import unittest
  
  import disjoint
  
  
  class TestDisjoint(unittest.TestCase):
      def setUp(self):
          self.ds = disjoint.Disjoint([1,2,3])
  
      def tearDown(self):
          self.ds = None
  
      def test_join_root1(self):
          self.ds.join(1, 2)
          self.assertEqual(self.ds.root(1), self.ds.root(2))
          self.ds.join(2, 3)
          self.assertEqual(self.ds.root(1), self.ds.root(3))
  
      def test_join_root2(self):
          self.ds.join(1, 2)
          self.assertEqual(self.ds.root(1), self.ds.root(1))
          self.assertEqual(self.ds.root(1), self.ds.root(2))
          self.assertNotEqual(self.ds.root(1), self.ds.root(3))
  
  